Identification and biosynthesis of tropone derivatives and sulfur volatiles produced by bacteria of the marine Roseobacter clade
作者:Verena Thiel、Thorsten Brinkhoff、Jeroen S. Dickschat、Susanne Wickel、Jörg Grunenberg、Irene Wagner-Döbler、Meinhard Simon、Stefan Schulz
DOI:10.1039/b909133e
日期:——
Bacteria of the Roseobacter clade are abundant marine bacteria and are important contributors to the global sulfur cycle. The volatiles produced by two of its members, Phaeobacter gallaeciensis and Oceanibulbus indolifex, were analyzed to investigate whether the released compounds are derived from sulfur metabolism, and which biosynthetic pathways are involved in their formation. Both bacteria emitted different sulfides and thioesters, including new natural compounds such as S-methyl phenylethanethioate (16) and butyl methanesulfonate (21). The S-methyl alkanoates were identified by comparison with standards that were synthesized from the respective methyl alkanoates by a new method using an easily prepared aluminium/sulfur reagent. Phaeobacter gallaeciensis is also able to produce tropone (37) in large amounts. Its biosynthesis was investigated by various feeding experiments, showing that 37 is formed via a deviation of the phenylacetate catabolism. The unstable tropone hydrate 42 was identified as an intermediate of the tropone biosynthesis that was also released together with tropolone (38).
Roseobacter 支系的细菌是丰富的海洋细菌,是全球硫循环的重要贡献者。研究人员分析了其中两个成员 Phaeobacter gallaeciensis 和 Oceanibulbus indolifex 产生的挥发性物质,以研究释放的化合物是否来自硫代谢,以及形成这些化合物的生物合成途径。两种细菌都释放出不同的硫化物和硫代酯,包括新的天然化合物,如 S-甲基苯硫酸盐(16)和甲基磺酸丁酯(21)。这些 S-甲基烷酸酯是通过与标准品进行比较而鉴定出来的,标准品是通过使用一种易于制备的铝/硫试剂的新方法从相应的甲基烷酸酯中合成的。加拉埃希氏芽孢杆菌也能大量生产托品酮(37)。通过各种喂养实验对其生物合成进行了研究,结果表明 37 是通过苯乙酸分解代谢的偏差形成的。不稳定的托品酮水合物 42 被确定为托品酮生物合成的中间产物,它也会与托品酮一起释放出来(38)。